Mobile terminals with multiple Subscriber Identity Modules (SIMs) have increased in popularity in recent years. The complexity of multi-SIM designs may depend on the flexibility in operation desired for each included SIM. For example, multi-SIM designs known as Single Receive Dual-SIM Dual-Standby (SR-DSDS) may incorporate two separate SIMs but may only provide a single transceiver system. As a result, only one SIM may be able to actively transmit and receive voice or packet data at a given time. Both SIMs may still be able to operate passively (hence “standby”) and may utilize a time-multiplexing scheme in which both SIMs alternatively share use of the transceiver.
Dual-Receive Dual-SIM Dual-Standby (DR-DSDS) designs may allow both SIMs to concurrently receive data by incorporating two separate receiver subsystems (i.e. receive chain). Each SIM may thus be granted exclusive use of one of the receiver subsystems and accordingly may receive data without interruption from the other SIM. However, DR-DSDS designs may provide only a single transmitter subsystem, and a result only one SIM may be able to transmit data at a given time.
Dual-SIM Dual-Active (DSDA) designs may expand on DR-DSDS multi-SIM designs by providing two separate transceiver systems. Each SIM may thus be granted exclusive access to one of the transceiver systems and may be able to both transmit and receive data independently in parallel with the other SIM.